Battery heating circuits and methods using resonance components in series based on charge balancing

ABSTRACT

Certain embodiments of the present invention disclose a battery heating circuit, wherein: the battery comprises a battery E 1  and a battery E 2 . For example, the heating circuit comprises: a first charging/discharging circuit, which is connected with the battery E 1 , and comprises a damping component R 1 , a current storage component L 1 , a first switch unit  1  and a charge storage component C, all of which are connected in series to each other; and a second charging/discharging circuit, which is connected to the battery E 2 , and comprises a damping component R 2 , a current storage component L 2 , a second switch unit  2  and the charge storage component C, all of which are connected in series with each other.

1. CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation-in-part of U.S. patent application Ser.No. 13/185,756, which claims priority to Chinese Patent Application No.201010245288.0, filed Jul. 30, 2010, Chinese Patent Application No.201010274785.3, filed Aug. 30, 2010, and Chinese Patent Application No.201110132362.2, filed May 20, 2011, all these four applications beingincorporated by reference herein for all purposes.

Additionally, this application is related to International ApplicationPublication No. WO2010/145439A1 and Chinese Application Publication No.CN102055042A, both these two applications being incorporated byreference herein for all purposes.

2. BACKGROUND OF THE INVENTION

The present invention pertains to electric and electronic field, inparticular related to a battery heating circuit.

Considering cars need to run under complex road conditions andenvironmental conditions or some electronic devices are used under harshenvironmental conditions, the battery, which serves as the power supplyunit for electric-motor cars or electronic devices, need to be adaptiveto these complex conditions. In addition, besides these conditions, theservice life and charge/discharge cycle performance of the battery needto be taken into consideration; especially, when electric-motor cars orelectronic devices are used in low temperature environments, the batteryneeds to have outstanding low-temperature charge/discharge performanceand higher input/output power performance.

Usually, under low temperature conditions, the resistance of the batterywill increase, and so will the polarization; therefore, the capacity ofthe battery will be reduced.

To keep the capacity of the battery and improve the charge/dischargeperformance of the battery under low temperature conditions, someembodiments of the present invention provide a battery heating circuit.

3. BRIEF SUMMARY OF THE INVENTION

The objective of certain embodiments of the present invention is toprovide a battery heating circuit, in order to solve the problem ofdecreased capacity of the battery caused by increased resistance andpolarization of the battery under low temperature conditions.

Certain embodiments of the present invention provide a battery heatingcircuit, wherein: the battery comprises a battery E1 and a battery E2,the heating circuit comprises: a first charging/discharging circuit,which is connected with the battery E1, and comprises a dampingcomponent R1, a current storage component L1, a first switch unit and acharge storage component C, all of which are connected in series to eachother; and a second charging/discharging circuit, which is connected tothe battery E2, and comprises a damping component R2, a current storagecomponent L2, a second switch unit and the charge storage component C,all of which are connected in series with each other.

The battery heating circuit provided in certain embodiments of thepresent invention can be used to heat up multiple batteriessimultaneously, or heat up some batteries among the multiple batteriesseparately by controlling the first switch unit and/or the second switchunit. In addition, if the electric quantities in the batteries areunbalanced among them, the battery heating circuit provided in certainembodiments of the present invention can be used to make the batterieswith electric quantity more than the average electric quantity transferthe excessive electric quantity into the charge storage component Cthrough a charging/discharging circuit; then, the energy stored in thecharge storage component C can be transfers to batteries with lesselectric quantity through another charging/discharging circuit, so as toattain the objective of electric quantity balance among the batteriesaccording to some embodiments.

Other characteristics and advantages of the present invention will befurther described in detail in the following section for embodiments.

4. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, as a part of this description, are providedhere to facilitate further understanding of the present invention, andare used in conjunction with the following embodiments to explain thepresent invention, but shall not be comprehended as constituting anylimitation on the present invention. In the figures:

FIG. 1 is a schematic diagram showing a battery heating circuitaccording to one embodiment of the present invention;

FIGS. 2A-2F are schematic diagrams showing the switch units as parts ofthe battery heating circuit as shown in FIG. 1 according to certainembodiments of the present invention;

FIG. 3 is a schematic diagram showing a battery heating circuitaccording to another embodiment of the present invention;

FIGS. 4A-4C are schematic diagrams showing the polarity inversion unitas part of the battery heating circuit as shown in FIG. 3 according tosome embodiments of the present invention;

FIG. 4D is a schematic diagram showing the DC-DC module for the polarityinversion unit as part of the battery heating circuit as shown in FIG.4C according to one embodiment of the present invention;

FIG. 5A is a schematic diagram showing a battery heating circuitaccording to yet another embodiment of the present invention;

FIG. 5B is a timing diagram of waveforms of the battery heating circuitas shown in FIG. 5A according to one embodiment of the presentinvention;

FIG. 6A is a schematic diagram showing a battery heating circuitaccording to yet another embodiment of the present invention;

FIG. 6B is a timing diagram of waveforms of the battery heating circuitas shown in FIG. 6A according to one embodiment of the presentinvention.

5. DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the present invention are described in detailbelow, with reference to the accompanying drawings. It should beappreciated that the embodiments described here are only provided todescribe and explain the present invention, but shall not be deemed asconstituting any limitation on the present invention.

It is noted that, unless otherwise specified, when mentioned hereafterin this description, the term “switching control module” may refer toany controller that can output control commands (e.g., pulse waveforms)under preset conditions or at preset times and thereby control theswitch unit connected to it to switch on or switch off accordingly,according to some embodiments. For example, the switching control modulecan be a PLC. Unless otherwise specified, when mentioned hereafter inthis description, the term “switch” may refer to a switch that enablesON/OFF control by using electrical signals or enables ON/OFF control onthe basis of the characteristics of the component according to certainembodiments. For example, the switch can be either a one-way switch(e.g., a switch composed of a two-way switch and a diode connected inseries, which can be conductive in one direction) or a two-way switch(e.g., a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) oran IGBT with an anti-parallel freewheeling diode). Unless otherwisespecified, when mentioned hereafter in this description, the term“two-way switch” may refer to a switch that can be conductive in twodirections, which can enable ON/OFF control by using electrical signalsor enable ON/OFF control on the basis of the characteristics of thecomponent according to some embodiments. For example, the two-way switchcan be a MOSFET or an IGBT with an anti-parallel freewheeling diode.Unless otherwise specified, when mentioned hereafter in thisdescription, the term “one-way semiconductor component” may refer to asemiconductor component that can be conductive in one direction, such asa diode, according to certain embodiments. Unless otherwise specified,when mentioned hereafter in this description, the term “charge storagecomponent” may refer to any device that can enable charge storage, suchas a capacitor, according to some embodiments. Unless otherwisespecified, when mentioned hereafter in this description, the term“current storage component” may refer to any device that can storecurrent, such as an inductor, according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “forward direction” may refer to the direction in which the energyflows from the battery to the energy storage circuit, and the term“reverse direction” may refer to the direction in which the energy flowsfrom the energy storage circuit to the battery, according to someembodiments. Unless otherwise specified, when mentioned hereafter inthis description, the term “battery” may comprise primary battery (e.g.,dry battery or alkaline battery, etc.) and secondary battery (e.g.,lithium-ion battery, nickel-cadmium battery, nickel-hydrogen battery, orlead-acid battery, etc.), according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “damping component” may refer to any device that inhibits currentflow and thereby enables energy consumption, such as a resistor, etc.,according to some embodiments. Unless otherwise specified, whenmentioned hereafter in this description, the term “main loop” may referto a loop composed of battery, damping component, switch unit and energystorage circuit connected in series according to certain embodiments.

It should be noted specially that, considering different types ofbatteries have different characteristics, in some embodiments of thepresent invention, “battery” may refer to an ideal battery that does nothave internal parasitic resistance and parasitic inductance or has verylow internal parasitic resistance and parasitic inductance, or may referto a battery pack that has internal parasitic resistance and parasiticinductance; therefore, those skilled in the art should appreciate thatif the battery is an ideal battery that does not have internal parasiticresistance and parasitic inductance or has very low internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery and the current storagecomponent L1 may refer to a current storage component external to thebattery; if the battery is a battery pack that has internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery or refer to the parasiticresistance in the battery pack, and the current storage component L1 mayrefer to a current storage component external to the battery or refer tothe parasitic inductance in the battery pack, according to certainembodiments.

To ensure the normal service life of the battery, according to someembodiments, the battery can be heated under low temperature condition,which is to say, when the heating condition is met, the heating circuitis controlled to start heating for the battery; when the heating stopcondition is met, the heating circuit is controlled to stop heating,according to certain embodiments.

In the actual application of battery, the battery heating condition andheating stop condition can be set according to the actual ambientconditions, to ensure normal charge/discharge performance of thebattery, according to some embodiments.

FIG. 1 is a schematic diagram of the battery heating circuit provided inone embodiment of the present invention. As shown in FIG. 1, oneembodiment of the present invention provides a battery heating circuit,wherein: the battery comprises a battery E1 and a battery E2, theheating circuit comprises: a first charging/discharging circuit, whichis connected with the battery E1, and comprises a damping component R1,a current storage component L1, a first switch unit 1 and a chargestorage component C, all of which are connected in series to each other;and a second charging/discharging circuit, which is connected to thebattery E2, and comprises a damping component R2, a current storagecomponent L2, a second switch unit 2 and the charge storage component C,all of which are connected in series with each other.

Wherein: the damping component R1 and damping component R2 can be theparasitic resistance in the battery E1 and battery E2 respectively; thecurrent storage component L1 and current storage component L2 can be theparasitic inductance in the battery E1 and battery E2 respectively.

Wherein: the heating circuit can further comprise a switching controlmodule 100, which is connected with the first switch unit 1 and secondswitch unit 2, and the switching control module 100 is configured tocontrol ON/OFF of the first switch unit 1 and second switch unit 2, sothat the energy flows back-and-forth between the battery E1 and thefirst charging/discharging circuit and/or flows back-and-forth betweenthe battery E2 and the second charging/discharging circuit when theswitch unit 1 and/or the second switch unit 2 switch(es) on, so that thedamping component R1 and/or damping component R2 generate(s) heat, andthereby attain the objective of heating up the battery.

The switching control module 100 can be a separate controller, which, byusing internal program setting, achieves ON/OFF control of differentexternal switches; or, the switching control module 100 can be aplurality of controllers, for example, a switching control module 100can be set for each external switch; or, the plurality of switchingcontrol modules 100 can be integrated into an assembly. Certainembodiments of the present invention do not impose any limitation to theform of implementation of the switching control module 100.

Preferably, the switching control module 100 is configured to controlthe first switch unit 1 to switch on and control the second switch unit2 to switch off so that the battery E1 charges the charge storagecomponent C, when the electric quantity in the battery E1 is more thanthe electric quantity in the battery E2; then, control the first switchunit 1 to switch off and control the second switch unit 2 to switch on,so that the charge storage component C charges the electric quantitystored in it into the battery E2, when the current flowing through thefirst charging/discharging circuit reaches zero after the positive halfcycle, so as to achieve the objective of energy balance between thebatteries.

FIGS. 2A-2F are schematic diagrams of embodiments of the first switchunit and/or the second switch unit shown in FIG. 1. Hereunder theembodiments of the first switch unit and/or second switch unit will bedetailed, with reference to FIG. 2A-2F.

To achieve to-and-fro energy flow between the battery and thecharging/discharging circuit, in one embodiment of the presentinvention, the first switch unit 1 and/or second switch unit 2 can betwo-way switches K3, as shown in FIG. 2A. The switching control module100 controls ON/OFF of the two-way switch K3; when the battery is to beheat up, the two-way switch K3 can be controlled to switch on; ifheating is to be paused or is not needed, the two-way switch K3 can becontrolled to switch off.

Employing a separate two-way switch K3 to implement the switch unit cansimplify the circuit, reduce system footprint, and simplify theimplementation; however, to implement cut-off of reverse current, thefollowing embodiment of the switch unit is further provided in thepresent invention.

Preferably, the switch unit 1 and/or second switch unit 2 can comprise afirst one-way branch configured to implement energy flow from thebattery to the charging/discharging circuit, and a second one-way branchconfigured to implement energy flow from the charging/dischargingcircuit to the battery; wherein: the switching control module 100 isconnected to either or both of the first one-way branch and secondone-way branch, to control ON/OFF the connected branches.

When the battery is to be heated, both the first one-way branch and thesecond one-way branch can be controlled to switch on; when heating is tobe paused, either or both of the first one-way branch and the secondone-way branch can be controlled to switch off; when heating is notneeded, both of the first one-way branch and the second one-way branchcan be controlled to switch off. Preferably, both of the first one-waybranch and the second one-way branch are subject to the control of theswitching control module 100; thus, energy flow in forward direction andreverse direction can be implemented flexibly.

In another embodiment of the switch units, as shown in FIG. 2B, thefirst switch unit 1 and/or second switch unit 2 can comprise a two-wayswitch K4 and a two-way switch K5, wherein: the two-way switch K4 andtwo-way switch K5 are connected in series opposite to each other, toform the first one-way branch and the second one-way branch; theswitching control module 100 is connected with the two-way switch K4 andthe two-way switch K5 respectively, to control ON/OFF of the firstone-way branch and second one-way branch by controlling ON/OFF of thetwo-way switch K4 and two-way switch K5.

When the battery is to be heated, the two-way switches K4 and K5 can becontrolled to switch on; when heating is to be paused, either or both ofthe two-way switch K4 and two-way switch K5 can be controlled to switchoff; when heating is not needed, both of the two-way switch K4 andtwo-way switch K5 can be controlled to switch off. In such animplementation of switch units, the first one-way branch and the secondone-way branch can be controlled separately to switch on or off, andtherefore energy flow in forward direction and reverse direction in thecircuit can be implemented flexibly.

In another embodiment of the switch units, as shown in FIG. 2C, thefirst switch unit 1 and/or second switch unit 2 can comprise a switchK6, a one-way semiconductor component D11 and a one-way semiconductorcomponent D12, wherein: the switch K6 and the one-way semiconductorcomponent D11 are connected in series with each other to form the firstone-way branch; the one-way semiconductor component D12 forms the secondone-way branch; the switching control module 100 is connected with theswitch K6, to control ON/OFF of the first one-way branch by controllingON/OFF of the switch K6. In the switch unit shown in FIG. 2C, whenheating is needed, the switch K6 can be controlled to switch on; whenheating is not needed, the switch K6 can be controlled to switch off.

Though the implementation of switch units shown in FIG. 2C implementsto-and-fro energy flow along separate branches, it can't implementenergy flow cut-off function in reverse direction. The present inventionfurther puts forward another embodiment of switch units, as shown inFIG. 2D, the first switch unit 1 and/or second switch unit 2 can furthercomprise a switch K7 in the second one-way branch, wherein: the switchK7 is connected with the one-way semiconductor component D12 in series,the switching control module 100 is also connected with the switch K7,and the switching control module 100 is configured to control ON/OFF ofthe second one-way branch by controlling ON/OFF of the switch K7. Thus,in the switch unit shown in FIG. 2D, since switches (i.e., switch K6 andswitch K7) exist in both one-way branches, energy flow cut-off functionin forward direction and reverse direction is implemented.

Preferably, the first switch unit 1 and/or second switch unit 2 canfurther comprise a resistor connected with the first one-way branchand/or second one-way branch, to reduce the current in thecharging/discharging circuit, so as to avoid damage to the batteries dueto over-current. For example, a resistor R6 connected in series with thetwo-way switch K4 and two-way switch K5 can be added in the switch unitsshown in FIG. 2B, to obtain another implementation of the switch units,as shown in FIG. 2E. FIG. 2F shows one embodiment of the switch units,which is obtained by connecting resistor R3 and resistor R4 in series inthe two one-way branches in the switch units shown in FIG. 2D,respectively.

In one embodiment in which the energy flows back-and-forth between thebattery and the charging/discharging circuit, the switch unit can beswitched off at any point of time in one or more cycles, which is tosay, the switch unit can be switched off at any time, for example, theswitch unit can be switched off when the current flows through theswitch unit in forward direction or reverse direction, and is equal tozero or not equal to zero. A specific implementation form of switch unitcan be selected, depending on the needed cut-off strategy; if onlycurrent flow cut-off in forward direction is needed, the implementationform of switch unit shown in FIG. 2A or FIG. 2C can be selected; ifcurrent flow cut-off in forward direction and reverse direction isneeded, the switch unit with two controllable one-way branches shown inFIG. 2B or FIG. 2D can be selected.

FIG. 3 is a schematic diagram of one embodiment of the battery heatingcircuit provided in the present invention. As shown in FIG. 3, theheating circuit provided in one embodiment of the present invention canfurther comprise a polarity inversion unit 101, which is connected withthe charge storage component C, and the polarity inversion unit 101 isconfigured to invert the voltage polarity of the charge storagecomponent C. The switching control module 100 is connected with thefirst switch unit 1, second switch unit 2 and polarity inversion unit101, and is configured to control the first switch unit 1 and/or thesecond switch unit 2 to switch off when the current flowing through thefirst charging/discharging circuit and/or the secondcharging/discharging circuit reaches zero after the negative half cycle,and then control the polarity inversion unit 101 to invert the voltagepolarity of the charge storage component C. Since the voltage across thecharge storage component C after polarity inversion can be addedserially with the voltage of battery E1 and voltage of battery E2, thecurrent in the first charging/discharging circuit and/or secondcharging/discharging circuit can be increased when the first switch unit1 and/or second switch unit 2 switches on again.

FIG. 4A-4C are schematic diagrams of one embodiment of the polarityinversion unit shown in FIG. 3. Hereunder the embodiments of thepolarity inversion unit 101 will be detailed, with reference to FIG.4A-FIG. 4C.

In one embodiment of the polarity inversion unit 101, as shown in FIG.4A, the polarity inversion unit 101 comprises a single-pole double-throwswitch J1 and a single-pole double-throw switch J2, wherein: thesingle-pole double-throw switch J1 is arranged at one end of the chargestorage component C and the single-pole double-throw switch J2 isarranged at the other end of the charge storage component C; the inputwire of the single-pole double-throw switch J1 is connected in the firstand second charging/discharging circuits, the first output wire of thesingle-pole double-throw switch J1 is connected to the first pole plateof the charge storage component C, and the second output wire of thesingle-pole double-throw switch J1 is connected to the second pole plateof the charge storage component C; the input wire of the single-poledouble-throw switch J2 is connected in the first and secondcharging/discharging circuits, the first output wire of the single-poledouble-throw switch J2 is connected to the second pole plate of thecharge storage component C, and the second output wire of thesingle-pole double-throw switch J2 is connected to the first pole plateof the charge storage component C; the switching control module 100 isalso connected with the single-pole double-throw switch J1 andsingle-pole double-throw switch J2 respectively, and is configured toinvert the voltage polarity of the charge storage component C bychanging the connection relationships between the respective input wireand output wires of the single-pole double-throw switch J1 and thesingle-pole double-throw switch J2.

In that embodiment, the connection relationships between the respectiveinput wire and output wires of the single-pole double-throw switch J1and single-pole double-throw switch J2 can be set in advance, so thatthe input wire of the single-pole double-throw switch J1 is connectedwith the first output wire of the single-pole double-throw switch J1,while the input wire of the single-pole double-throw switch J2 isconnected with the first output wire of the single-pole double-throwswitch J2. When the first switch unit 1 and the second switch unit 2switch off; the input wire of the single-pole double-throw switch J1 canbe switched to connect with the second output wire of the single-poledouble-throw switch J1, while the input wire of the single-poledouble-throw switch J2 is switched to connect to the second output wireof the single-pole double-throw switch J2, under control of theswitching control module 100, when the first switch unit 1 and secondswitch unit 2 switch off, so as to attain the objective of voltagepolarity inversion of the charge storage component C.

In another embodiment of the polarity inversion unit 101, as shown inFIG. 4B, the polarity inversion unit 101 comprises a one-waysemiconductor component D3, a current storage component L3 and a switchK9, all of which are connected in series with each other, and the seriescircuit is connected in parallel between the ends of the charge storagecomponent C; the switching control module 100 is also connected with theswitch K9, and is configured to invert the voltage polarity of thecharge storage component C by controlling the switch K9 to switch on.

In that embodiment, when the first switch unit 1 and second switch unit2 switch off, the switch K9 can be controlled by the switching controlmodule 100 to switch on, and thereby the charge storage component C,one-way semiconductor component D3, current storage component L3 andswitch K9 form a LC oscillation circuit, and the charge storagecomponent C discharges via the current storage component L3; when thecurrent flowing through the current storage component L3 reaches zeroafter the negative half cycle of current flowing through the oscillationcircuit, the voltage polarity of the charge storage component C will beinverted.

In another embodiment of the polarity inversion unit 101, as shown inFIG. 4C, the polarity inversion unit 101 comprises a DC-DC module 102and a charge storage component C1, wherein: the DC-DC module 102 isconnected in series with the charge storage component C and the chargestorage component C1 respectively; the switching control module 100 isalso connected with the DC-DC module 102, and is configured to transferthe energy in the charge storage component C to the charge storagecomponent C1 and then transfer back the energy in the charge storagecomponent C1 to the charge storage component C by controlling the DC-DCmodule 102 to operate, so as to invert the voltage polarity of thecharge storage component C.

The DC-DC module 102 is a DC-DC conversion circuit for voltage polarityinversion commonly used in the field. Certain embodiments of the presentinvention do not impose any limitation to the specific circuit structureof the DC-DC module 102, as long as the module can accomplish voltagepolarity inversion of the charge storage component C. Those skilled inthe art can add, replace, or delete the components in the circuit asneeded.

FIG. 4D is a schematic diagram of one embodiment of the DC-DC module 102provided in the present invention. As shown in FIG. 4D, the DC-DC module102 comprises: a two-way switch Q1, a two-way switch Q2, a two-wayswitch Q3, a two-way switch Q4, a first transformer T1, a one-waysemiconductor component D4, a one-way semiconductor component D5, acurrent storage component L4, a two-way switch Q5, a two-way switch Q6,a second transformer T2, a one-way semiconductor component D6, a one-waysemiconductor component D7 and a one-way semiconductor component D8.

In the embodiment, the two-way switch Q1, two-way switch Q2, two-wayswitch Q3 and two-way switch Q4 are MOSFETs; the two-way switch Q5 andtwo-way switch Q6 are IGBTs.

The Pin 1, 4 and 5 of the first transformer T1 are dotted terminals; thepin 2 and 3 of the second transformer T2 are dotted terminals.

Wherein: the positive electrode of the one-way semiconductor componentD7 is connected with the end ‘a’ of the charge storage component C1, andthe negative electrode of the one-way semiconductor component D7 isconnected with the drain electrode of the two-way switch Q1 and two-wayswitch Q2, respectively; the source electrode of the two-way switch Q1is connected with the drain electrode of the two-way switch Q3, and thesource electrode of the two-way switch Q2 is connected with the drainelectrode of the two-way switch Q4; the source electrodes of the two-wayswitch Q3 and two-way switch Q4 are connected with the end ‘b’ of thecharge storage component C1 respectively; thus, a full-bridge circuit isformed; here, the voltage polarity of the charge storage component C1is: end ‘a’ is positive, while end ‘b’ is negative.

In the full-bridge circuit, the two-way switch Q1 and two-way switch Q2constitute the upper bridge arm, while the two-way switch Q3 and two-wayswitch Q4 constitute the lower bridge arm. The full-bridge circuit isconnected with the charge storage component C1 via the first transformerT1; the pin 1 of the first transformer T1 is connected with the firstnode N1, the pin 2 of the transformer T1 is connected with the secondnode N2, the pin 3 and pin 5 of the transformer T1 are connected to thepositive electrode of the one-way semiconductor component D4 and thepositive electrode of the one-way semiconductor component D5,respectively; the negative electrode of one-way semiconductor componentD4 and the negative electrode of one-way semiconductor component D5 areconnected with one end of the current storage component L4, and theother end of the current storage component L4 is connected with the end‘d’ of the charge storage component C1; the pin 4 of the transformer T1is connected with the end ‘c’ of the charge storage component C1, thepositive electrode of the one-way semiconductor component D8 isconnected with the end ‘d’ of the charge storage component C1, and thenegative electrode of the one-way semiconductor component D8 isconnected with the end ‘b’ of the charge storage component C1; here, thevoltage polarity of the charge storage component C1 is: end ‘c’ isnegative, while end ‘d’ is positive.

Wherein: the end ‘c’ of the charge storage component C1 is connectedwith the emitter electrode of the two-way switch Q5, the collectorelectrode of the two-way switch Q5 is connected with the pin 2 of thetransformer T2, the pin 1 of the transformer T2 is connected with end‘a’ of the charge storage component C, the pin 4 of the transformer T2is connected with end ‘a’ of the charge storage component C, the pin 3of the transformer T2 is connected with the positive electrode of theone-way semiconductor component D6, the negative electrode of theone-way semiconductor component D6 is connected with the collectorelectrode of the two-way switch Q6, and the emitter electrode of thetwo-way switch Q6 is connected with the end ‘b’ of the charge storagecomponent C1.

Wherein: the two-way switch Q1, two-way switch Q2, two-way switch Q3,two-way switch Q4, two-way switch Q5 and two-way switch Q6 arecontrolled by the switching control module 100 respectively to switch onand switch off.

Hereunder the working process of the DC-DC module 102 will be described:

1. After the first switch unit 1 and second switch unit 2 switch off,the switching control module 100 controls the two-way switch Q5 andtwo-way switch Q6 to switch off, and control the two-way switch Q1 andtwo-way switch Q4 to switch on at the same time, to form phase A;control the two-way switch Q2 and two-way switch Q3 to switch on at thesame time, to form phase B; by controlling the phase A and phase B toswitch on in alternate, a full-bridge circuit is formed;

2. When the full-bridge circuit operates, the energy in the chargestorage component C is transferred through the first transformer T1,one-way semiconductor component D4, one-way semiconductor component D5and current storage component L4 to the charge storage component C1;now, the voltage polarity of the charge storage component C1 is: end ‘c’is negative, while end ‘d’ is positive.

3. The switching control module 100 controls the two-way switch Q5 togate on, and therefore a path from the charge storage component C1 tothe charge storage component C is formed via the second transformer T2and the one-way semiconductor component D8; thus, the energy in thecharge storage component C1 is transferred back to the charge storagecomponent C, wherein: some energy will be stored in the secondtransformer T2; now, the switching control module 100 controls thetwo-way switch Q5 to gate off and controls the two-way switch Q6 to gateon, and therefore the energy stored in the second transformer T2 istransferred to the charge storage component C via the second transformerT2 and the one-way semiconductor component D6; now, the voltage polarityof the charge storage component C is inverted to: end ‘a’ is negative,while end ‘b’ is positive. Thus, the objective of inverting the voltagepolarity of the charge storage component C is attained.

FIG. 5A is a schematic diagram of the second embodiment of the batteryheating circuit provided in the present invention. As shown in FIG. 5A,the first switch unit 1 is a switch K1 a, the second switch unit 2 is aswitch K1 b, the polarity inversion unit 101 comprises a one-waysemiconductor component D3, a switch K9 and a current storage componentL3, which are connected in series with each other, and the seriescircuit is connected in parallel between the ends of the charge storagecomponent C, so as to invert the voltage polarity of the charge storagecomponent C.

FIG. 5B is a timing sequence diagram of the waveforms corresponding tothe heating circuit as shown in FIG. 5A. According to one embodiment,hereunder the operating process of the heating circuit as shown in FIG.5A will be detailed, with reference to FIG. 5B. First, the switchingcontrol module 100 controls the switch K1 a and the switch K1 b toswitch on, and controls the switch K9 to switch off. Now, the battery E1and the battery E2 charge the charge storage component C simultaneously(see time period t1); when the current I_(E1) flowing through thebattery E1 and the current I_(E2) flowing through the battery E2 reachzero after the positive half cycle, the voltage V_(C) across the chargestorage component reaches the peak value, and the charge storagecomponent C starts to charge back the energy stored in it to the batteryE1 and the battery E2, and the back-charge ends when the current I_(E1)and the current I_(E2) reach zero after the negative half cycle (seetime period t2); then, the switching control module 100 controls theswitch K1 a and the switch K1 b to switch off, and controls the switchK9 to switch on; now, the polarity inversion unit 101 starts to invertthe voltage polarity of the charge storage component C, and the polarityinversion ends when the current I_(C) flowing through the charge storagecomponent C reaches zero after the negative half cycle (see time periodt3, at this point, a complete working cycle T has just finished); then,the switching control module 100 controls the switch K9 to switch off.Next, above cycle can be repeated, so that the current flowing throughthe damping component R1 and the damping component R2 continues, andtherefore the damping component R1 and the damping component R2 generateheat, so as to heat up the battery E1 and battery E2, according tocertain embodiments.

FIG. 5B shows the case that the battery E1 and battery E2 are heated upsimultaneously. Of course, the first switch unit 1 and the second switchunit 2 can be controlled as needed, so as to heat up either batteryseparately according to another embodiment. In addition, for example,the switch-off control of the switch K1 a and the switch K1 b can beconducted within the grid section as shown in FIG. 5B.

FIG. 6A is a schematic diagram of a third embodiment of the batteryheating circuit provided in the present invention. As shown in FIG. 6A,the first switch unit 1 comprises a first one-way branch composed of aswitch K6 a and a one-way semiconductor component D11 a connected inseries and a second one-way branch composed of a switch K7 a and aone-way semiconductor component D12 a connected in series; the firstone-way branch and the second one-way branch are connected in parallelopposite to each other. Additionally, the second switch unit 2 comprisesa first one-way branch composed of a switch K6 b and a one-waysemiconductor component D11 b connected in series and a second one-waybranch composed of a switch K7 b and a one-way semiconductor componentD12 b connected in series; the first one-way branch and the secondone-way branch are connected in parallel opposite to each other.Moreover, the polarity inversion unit 101 comprises a one-waysemiconductor component D3, a switch K9 and a current storage componentL3, which are connected in series with each other, and the seriescircuit is connected in parallel between the ends of the charge storagecomponent C, so as to invert the voltage polarity of the charge storagecomponent C.

FIG. 6B is a timing sequence diagram of the waveforms corresponding tothe heating circuit as shown in FIG. 6A. According to one embodiment,hereunder the operating process of the heating circuit as shown in FIG.6A will be detailed, with reference to FIG. 6B. First, the switchingcontrol module 100 controls the switch K6 a to switch on, and controlsthe switch K7 b, the switch K9, the switch K7 a and the switch K6 b toswitch off. Now, the battery E2 charges the charge storage component C(see time period t1); when the current I_(E2) flowing through thebattery E2 reaches zero after the positive half cycle, the switchingcontrol module 100 controls the switch K6 a to switch off and controlsthe switch K7 b to switch on, so that the charge storage component Cstarts to charge back the energy stored in it to the battery E1, and theback-charge ends when the current I_(E1) flowing through the battery E1reaches zero after the negative half cycle (see time period t2); then,the switching control module 100 controls the switch K6 a and the switchK7 b to switch off, and controls the switch K9 to switch on, so that thepolarity inversion unit 101 starts to invert the voltage polarity of thecharge storage component C, and the polarity inversion ends when thecurrent I_(C) flowing through the charge storage component C reacheszero after the negative half cycle (see time period t3, at this point, acomplete working cycle T has just finished); then, the switching controlmodule 100 controls the switch K9 to switch off. Next, above cycle canbe repeated, so that the energy in the battery E2 with more electricquantity flows into the charge storage component C, and then the energyflows via the charge storage component C to the battery E1 with lesselectric quantity, and thereby the objective of electric quantitybalance between the batteries is attained according to one embodiment.According to another embodiment, in addition, in that period, there iscurrent flowing through the damping component R1 and the dampingcomponent R2; therefore, the damping component R1 and the dampingcomponent R2 generate heat, and heat up the battery E1 and the batteryE2.

It should be noted that the objective of heating up the battery can beattained when the battery returns the energy to itself; and theobjective of heating up the battery and an energy balance function canbe attained when the battery returns the energy to itself and transferpartial energy to other batteries according to certain embodiments.Though a specific heating circuit for battery E1 and battery E2 is onlydescribed here, virtually the battery heating circuit can be extended toserve for multiple batteries, and can heat up all the batteriessimultaneously or heat up one or more batteries among the batteriesseparately, and achieve electric quantity balance among the batteries,according to certain embodiments. Moreover, the durations of the timeperiods are adjustable, so as to control the effective current values ofthe batteries according to some embodiments.

Certain embodiments of the present invention disclose a battery heatingcircuit, wherein: the battery comprises a battery E1 and a battery E2.For example, the heating circuit comprises: a first charging/dischargingcircuit, which is connected with the battery E1, and comprises a dampingcomponent R1, a current storage component L1, a first switch unit (1)and a charge storage component C, all of which are connected in seriesto each other; and a second charging/discharging circuit, which isconnected to the battery E2, and comprises a damping component R2, acurrent storage component L2, a second switch unit (2) and the chargestorage component C, all of which are connected in series with eachother. In another example, the battery heating unit provided in certainembodiments of the present invention is applicable to multiplebatteries, and can be used to heat up multiple batteries together orseparately, and achieve electric quantity balance among the batteries.

For example, some or all components of various embodiments of thepresent invention each are, individually and/or in combination with atleast another component, implemented using one or more softwarecomponents, one or more hardware components, and/or one or morecombinations of software and hardware components. In another example,some or all components of various embodiments of the present inventioneach are, individually and/or in combination with at least anothercomponent, implemented in one or more circuits, such as one or moreanalog circuits and/or one or more digital circuits.

While some embodiments of the present invention are described above withreference to the accompanying drawings, the present invention is notlimited to the details of those embodiments. Those skilled in the artcan make modifications and variations, without departing from the spiritof the present invention. However, all these modifications andvariations shall be deemed as falling into the scope of the presentinvention.

In addition, it should be noted that the specific technical featuresdescribed in the above embodiments can be combined in any appropriateway, provided that there is no conflict. To avoid unnecessaryrepetition, certain possible combinations are not describedspecifically. Moreover, the different embodiments of the presentinvention can be combined as needed, as long as the combinations do notdeviate from the spirit of the present invention. However, suchcombinations shall also be deemed as falling into the scope of thepresent invention.

Hence, although specific embodiments of the present invention have beendescribed, it will be understood by those of skill in the art that thereare other embodiments that are equivalent to the described embodiments.Accordingly, it is to be understood that the invention is not to belimited by the specific illustrated embodiments, but only by the scopeof the appended claims.

1. A circuit for heating one or more batteries, the circuit comprising:a first battery including a first damping component and a first currentstorage component, the first damping component and the first currentstorage component being parasitic to the first battery, the firstbattery including a first battery terminal and a second batteryterminal; a second battery including a second damping component and asecond current storage component, the second damping component and thesecond current storage component being parasitic to the second battery,the second battery including a third battery terminal and a fourthbattery terminal; a first switch unit; a second switch unit; a switchingcontrol component coupled to the first switch unit and the second switchunit; and a first charge storage component including a first storageterminal and a second storage terminal, the first charge storagecomponent and the first current storage component being at least partsof a first energy storage circuit, the first charge storage componentand the second current storage component being at least parts of asecond energy storage circuit; wherein: the first damping component, thefirst current storage component, the first switch unit, and the firstcharge storage component are connected; the second damping component,the second current storage component, the second switch unit, and thefirst charge storage component are connected; the switching controlcomponent is configured to turn on and off the first switch unit so asto control one or more first currents flowing from the first battery tothe first charge storage component and from the first charge storagecomponent to the first battery; and the switching control component isfurther configured to turn on and off the second switch unit so as tocontrol one or more second currents flowing from the second battery tothe first charge storage component and from the first charge storagecomponent to the second battery; wherein the circuit for heating one ormore batteries is configured to heat at least one battery selected fromthe first battery and the second battery by at least discharging andcharging at least the selected battery.
 2. The circuit of claim 1wherein: the first damping component is a first parasitic resistor ofthe first battery; the first current storage component is a firstparasitic inductor of the first battery; the second damping component isa second parasitic resistor of the second battery; and the secondcurrent storage component is a second parasitic inductor of the secondbattery.
 3. The circuit of claim 2 wherein the first charge storagecomponent is a capacitor.
 4. The circuit of claim 1 wherein theswitching control component is further configured to turn on the firstswitch unit and turn off the second switch unit and allow the one ormore first currents to flow from the first battery to the first chargestorage component and, after the one or more first currents reduce tozero in magnitude, turn off the first switch unit and turn on the secondswitch unit and allow the one or more second currents to flow from thefirst charge storage component to the second battery.
 5. The circuit ofclaim 4 wherein the switching control component is further configured toturn on the first switch unit and turn off the second switch unit andtransfer a first quantity of electric charge from the first battery tothe first charge storage component with the one or more first currentsand, after the one or more first currents reduce to zero in magnitude,turn off the first switch unit and turn on the second switch unit andtransfer a second quantity of electric charge from the first chargestorage component to the second battery with the one or more secondcurrents.
 6. The circuit of claim 1 wherein the first switch unitincludes a two-way switch.
 7. The circuit of claim 1 wherein the firstswitch unit includes a first branch circuit for conduction in a firstdirection and a second branch circuit for conduction in a seconddirection, the first direction being from the first battery to the firstcharge storage component, the second direction being from the firstcharge storage component to the first battery.
 8. The circuit of claim 7wherein: the first branch circuit includes a first switch and a firstone-way semiconductor component connected in series with the firstswitch, the first switch being coupled to the switching controlcomponent; and the second branch circuit includes a second one-waysemiconductor component; wherein the switching control component isfurther configured to turn on and off the first branch circuit byturning on and off the first switch respectively.
 9. The circuit ofclaim 8 wherein: the second branch circuit further includes a secondswitch coupled to the switching control component and connected inseries with the second one-way semiconductor component; wherein theswitching control component is further configured to turn on and off thesecond branch circuit by turning on and off the second switchrespectively.
 10. The circuit of claim 7 wherein the first switch unitfurther includes a resistor connected in series with at least the firstbranch circuit or the second branch circuit.
 11. The circuit of claim 1wherein the first switch unit includes: a first two-way switch coupledto the switch control unit; and a second two-way switch coupled to theswitch control unit and connected in series with the first two-wayswitch; wherein the switch control unit is further configured to turn onand off the first two-way switch and to turn on and off the secondtwo-way switch.
 12. The circuit of claim 1, and further comprising apolarity inversion unit coupled to the first charge storage componentand configured to invert a voltage polarity associated with the firstcharge storage component.
 13. The circuit of claim 12 wherein thepolarity inversion unit includes: a first single-pole double-throwswitch coupled to the first storage terminal of the first charge storagecomponent; and a second single-pole double-throw switch coupled to thesecond storage terminal of the first charge storage component; wherein:the first single-pole double-throw switch includes a first input wire, afirst output wire, and a second output wire; the first input wire iscoupled, directly or indirectly, to the first battery terminal and thethird battery terminal; and the first output wire and the second outputwire are coupled to the first storage terminal and the second storageterminal respectively; wherein: the second single-pole double-throwswitch includes a second input wire, a third output wire, and a fourthoutput wire; the second input wire is coupled, directly or indirectly,to the second battery terminal and the fourth battery terminal; and thethird output wire and the fourth output wire are coupled to the secondstorage terminal and the first storage terminal respectively; whereinthe switching control component is coupled to the first single-poledouble-throw switch and the second single-pole double-throw switch, andis configured to invert the voltage polarity associated with the firstcharge storage component by altering connection relationships among thefirst input wire, the first output wire, the second output wire, thesecond input wire, the third output wire, and the fourth output wire.14. The circuit of claim 12 wherein the polarity inversion unitincludes: a third switch; a third current storage component; and a firstone-way semiconductor component, a combination of the first one-waysemiconductor component, the third current storage component, and thethird switch being connected between the first storage terminal and thesecond storage terminal.
 15. The circuit of claim 12 wherein thepolarity inversion unit includes: a second charge storage component; anda first DC-DC module coupled to the second charge storage component andthe first charge storage component; wherein the switching controlcomponent is coupled to the first DC-DC module and configured to invertthe voltage polarity associated with the first charge storage componentby transferring energy from the first charge storage component to thesecond charge storage component and then transferring the energy fromthe second charge storage component back to the first charge storagecomponent.
 16. The circuit of claim 12 wherein: the switching controlcomponent is coupled to the polarity inversion unit; and the switchingcontrol component is further configured to: turn off the first switchunit or the second switch unit if the one or more first currents flowingfrom the first charge storage component to the first battery reduces tozero in magnitude or the one or more second currents flowing from thefirst charge storage component to the second battery reduces to zero inmagnitude; and then control the polarity inversion unit to invert thevoltage polarity associated with the first charge storage component. 17.The circuit of claim 12 wherein: the switching control component iscoupled to the polarity inversion unit; and the switching controlcomponent is further configured to: turn off the first switch unit andthe second switch unit if the one or more first currents flowing fromthe first charge storage component to the first battery reduces to zeroin magnitude and the one or more second currents flowing from the firstcharge storage component to the second battery reduces to zero inmagnitude; and then control the polarity inversion unit to invert thevoltage polarity associated with the first charge storage component. 18.The circuit of claim 1 is further configured to: start heating at leastthe selected battery if at least one heating start condition issatisfied; and stop heating at least the selected battery if at leastone heating stop condition is satisfied.